added access to deform weights, access to weights acts like a python dict so you can do...
print(group in dvert)
dvert[group] = 0.5
print(dvert[group])
del dvert[group]
print(dvert.items())
- add examples for custom-data access
- group BMesh types logically in docs
- added missing docstrings
needed to add grouping functionality to sphinx for this.